The Analytical Resources Core (ARC) has been an integral part of the VMMPC since it was founded in 2001. The ARC will consist of four subcores: 1) Hormone Assay and Analytical Services; 2) Lipids, Lipoproteins, and Atherosclerosis (LLA); 3) Mouse Pathology; and 4) Metabolic Flux Analysis (MFA). Throughout its history the ARC has operated at capacity with usage by investigators both inside and outside Vanderbilt. The ARC will undergo two major changes this cycle. The first change is that mouse atherosclerosis and plaque composition analyses will be moved to the ARC where they will be part of the Lipids, Lipoproteins and Atherosclerosis (LLA) Subcore. The second modification to the ARC is the creation of the Metabolic Flux Analysis (MFA) Subcore. The MFA Subcore involves the use of newly developed stable isotopic methods to assess metabolic flux in the conscious mouse or in vitro model systems. The goals of the core are to provide controlled, precision services that streamline research activities, produce cost-effective lines of experimentation, foster collaborative enterprises, and provide alternative outlets to scientists reaching the technical limits of their own laboratories. The services offered by each subcore are unique in their application to the mouse, and great effort has been made to establish assay specificity and scale down sample size to accommodate samples from this species. The Core provides space, equipment, and personnel for sample analyses and methods development. Investigators pay a fee-for-service that covers the cost of reagents, supplies, a percentage of personnel salary, and service contracts.